Alternating current and direct current secondary clock with individual rectifier



1 ,944,592 ARY Jan. 23, 1934.

W. BRYCE ALTERNATING CURRENT AND DIRECT CURRENT SECOND CLOCK WITH INDIVIDUAL RECTIFIER Filed Nov. 10, 1950 Z. 44 INVENTOR Patented Jan. 23, 1934 ALTERNATING CURRENT AND DIRECT CUR- RENT SECONDARY VIDUAL RECTIFIER CLOCK WITH INDI- James W. Bryce, Bloomfield, N. J? assignor, by

mesne assignments, to Internati nal Business Machines Corporation, New York, N. Y., a corporation of New York Application November 10, 1930 Serial No. 494,481

7 Claims. '(ol. 58-26) This invention relates to a system and method of actuating and regulating secondary clocks.

Among the objects of the present invention is to improve the system and secondary clock shown and described in previous James W. Bryce Patent No. 1,760,631, dated May 27, 1930.

More particularly the present invention is directed to an improved arrangement of secondary clocks adapted for operation on a synchronized clock system of the single wire type wherein A. C. and D. C. driving impulses are sent out from the master clock over the single circuit and wherein improved impulse accepting and rejecting means are provided in the secondary clock units for controlling their operation and synchronizing action.

A further object of the present invention resides in the provision of a system wherein provision is made in each of the secondary clocks for rectifying the current fiow in the clocks themselves upon the receipt of alternating current impulses by the clock.

Further and other objects of the present invention will be hereinafter set forth in the accompanying specification and claims and shown in the drawing, which by way of illustration shows what I now consider to be preferred embodiments of the invention.

In the drawing:

Figure l is one wiring diagram showing means by which secondary clocks may be actuated and regulated in accordance with the present invention;

Fig. 2 is a view of the actuating mechanism of one of the secondary clocks;

Fig. 3 shows a modified arrangement for a sec ondary clock in which full wave rectification in the secondary is secured; and

Fig. 4 shows another modified arrangement for secondary clocks wherein single wave rectification is secured and wherein only a single rectifying unit is providedin the secondary clock.

Referring to the drawing, designates a master clock which is of any conventional design, for example that shown in previous US. patent to James W. Bryce, No. 1,760,631, dated May 27,

- 1930. This master clock is adapted as is shown 'by the legend on the circuit diagram (Fig. 1) to send out over the single linecircuit 39 A. C. minute impulses beginning at the 60th minute and continuing to and inclusive of the 44th minute A. C. minute impulse. From the 45th minute to the 59th minute inclusive, D. C. impulses are sent out by the master clock. The master clock also sends out a series of D. C. rapid impulses, these being sent from a time shortly after the 59th minute to a time terminating before the th minute.

The construction of the master clock may be that shown in the aforementioned Bryce patent. The cam devices being properly timed to send the characteristic impulses at the times in question. 60 Other arrangements of master clocks may also be used provided these general conditions of sending impulses are satisfied.

Secondary clock The secondary clock illustrated in Fig. 2 is of conventional form and it includes a minute-hand arbor 20 which makes one revolution per hour. This arbor is advanced by means of an impulse magnet 21 which, acts through a ratchet wheel 22 to advance the minute hand arbor 20 step by step, as the magnet 21 receives successive electrical impulses from the master clock. Each minute hand arbor 20 carries a synchronizing cam 23. Cooperating with this cam 23 is a contact device including a blade 24 adapted to close contacts 25 when the high portion of the cam is under the blade 24 and to close contacts 26 when the blade 24 is on the low portion of the cam. The cam 23 is so timed that when the minute hand of the secondary clock is opposite the 59th minute the blade 24 has just fallen oil? the high point 27 of the cam, thereby breaking the contact 25* and making contact 26. The cam rise 28in the present embodiment of the invention is 35 disposed substantially 180 around the cam from the drop off point 2'7 so that at about 29 minutes after the hour, contacts 25 are closed and contacts 26 are opened. For reasons which will be self-evident from the subsequent description the point of rise 28 upon the cam may be positioned anywhereon the periphery of the cam prior to 44 minutes past the hour and exclusive of the synchronizing period.

According to the embodiment of the invention shown in Fig. 1, 40 designates'the lead in circuit of each secondary clock connected to the single supply circuit 39. In each secondary clock the supply circuit 40 is branched, one branch 41 extending to a dry plate rectifier unitv 42 and event'- ually connecting to the lower contact 26. The other branch 43 in the secondary clock leads through a dry plate rectifier unit 44 to the upper contact 25. The rectifying units are of the type now in the market and known as copper oxide rectifiers and comprise a series of plates. These rectifying units are arranged to permit passage of current flow in the direction indicated by the arrows and to impress and choke ofi current flow in the opposite direction.

In the drawing in Fig. 1, the master clock 10 is indicated by the 44th minute position. The X clock which is on time is also at the 44th minute position. The Y clock is indicated as 15 minutes fast and the Z clock as 15 minutes slow. It will be appreciated that with the clocks in this position the master clock has sent out its 44th minute impulse which is the last of the A. C. impulses. The next impulse sent out, viz, the 45th minute impulse, will be a D. C. impulse. Under these conditions the D. C. impulse will flow into the clock K through branch 43, rectitying unit 44, contacts 25 now closed, through blade 24, impulse magnet 21 to ground and back to the master clock. This clock will then continue its normal minute by minute advance in step with the master clock until the 59th minute is reached, at which time contacts 25 will open. Thereafter none of the fast impulses can flow 'into this clock since these are D. C. impulses and since circuit 43 is open at contacts 25. The branch circuit 41 while it is closed at 26 will be blocked by the choking action of the rectifying unit 42. Clock X will therefore reject all of the fast impulses and it will await the receipt of the first A. C. impulse which will occur at, the 60th minute. When such A. C. impulse is received,'

this impulse will flow through the circuit 41 through the rectifying unit 42, which unit will rectify the current characteristic of the impulse and permit it to flow through the impulse magnet 21 in the direction indicated by the arrow associated with rectifying unit 42. The clock then resumes its advance in synchronism with the master clock.

Now referring to clock Y and assuming again the timed conditions as in Fig. 1, clock Y is 15 minutes fast and has therefore reached the'59th minute, blade 24 having" dropped and opened up contacts 25. This clock is likewise arrested and cannot receive any of the D. C. impulses contacts remain closed all of the D. C. minute impulses will be received and in addition fifteen or the i'ast impulses will be received before the contacts 25 open and arrest the clock at the 59th minute. The clock Z will again step of! in synchronism" with the master clock at the th minute.

Referring now to Fig. 3, here is disclosed a' slightly modified arrangement of secondary clock in which provision is made for full wave rectification when A. C. impulses are received by the clock. The secondary clock includes the usual supply circult 40 with a branch circuit 41a leading through a condenser 45 and thence through the full wave rectify ng unit 46. This unit 46 has one terminal connected to contacts '25 and another terminal connected via wire 48 to impulse magnet 21 and another terminal connected through wire 49 to ground. The branch circuit 43a which extends to contacts 25 preferably includes a controlling resistance 47 but this resistance may be dispensed with depending upon voltage adjustment. Its use is, however, preferable. The general arrangement of the secondary clock with respect to its driving device, cam, etc., is the same as has previously been described in connection with Figs. 1 and 2. For D. C. operation, current will flow in from line 39 through 40, via branch 43a, through resistance 47, contacts 25, blade 24 through impulse magnet 21, wire 48 through one part of the rectifying unit 46 and back through wire 49 to ground and thence back to the master clock. With the blade in the other position, viz, down and closing contacts 26, the previously traced D. C. circuit is now open at contacts 25 and D. C. current cannot flow through magnet 21. The A. C. flow through the clock will be traced as follows: from wire 39 through 40, branch 41a, past condenser 45 through part of the rectifying unit 46, contacts 26, impulse magnet 21, back through another part of the rectifying unit and to ground through 49 and back to the master clock. The A. C. wave in the opposite direction comes up through 49, through part of the rectifying unit through 26, 21, 48 through another part of the rectifying unit cut through condenser 45, circuit 41a and back to line 39. In this way full wave rectification is obtained.

It will be understood that with contacts 25 open direct current cannot pass through the impulse magnet 21 because the condenser 45 blocks such flow of direct current impulses.

Fig. 4 shows a somewhat modified arrangement of the secondary clock shown. in Fig. 1. In this embodiment the rectifier unit 44 is dispensed with and in its place is substituted a resistance device 47a. The operation is the some previously traced for Fig. 1 except that in this arrangement there is a possibility of alternating current being supplied to magnet 21 under certain chronological conditions of the clock.- This action would occur only with unusually retarded conditions of the clock.

In secondary clocks it has been found in practice that D. C. operation is preferable for the impulse magnets because it gives a simpler, more powerfulaction on the magnets with less tendency for chattering and buzzing, which effects are noticed with magnets operated on single phase A. C.

According to the present invention the clocks are controlled for synchronism by the alternative use of A. C. and D. C., but in each secondary clock provision is made for rectifying received A. C. impulses and impressing on the impulse magnets either direct current or rectified alternating current. In this way uni-directional current flow through the impulse magnet is obtained with consequent improved action. of the secondary clocks.

' What Iclaim is" 1. A secondary c i with a supply circuit leading thereinto upon which A. C. and D. C. impulses are impressed, an impulse magnet of the D.C.type, an arbor shaft and pawl and ratchet devices actuated by the impulse magnet for imparting step by step advance to said shaft and a rectifying device in said secondary clock intermediate the supply circuit and the impulse magnet to supply currentof uni-directional characteristic to the said impulse magnet irrespective of the character of the current impulses supplied to the supply circuit by the master clock to prevent chattering action of the impulse magnet actuated clock parts.

2. A secondary clock adapted for use in a synchronized clock system wherein A. C. and unidirectional current is supplied over a single line supply circuit to the secondary clocks, said secondary clock comprising an arbor shaft, ratchet and lOl Ill

pawl devices for actuating said shaft and an impulse magnet of the direct current type for operating said pawl and ratchet devices and said shaft, said secondary clock being provided with a rectifying device in its magnet circuit for providing uni-directional flow through the magnet when alternating current is being received by the clock so that chattering actuation of the clock parts by the impulse magnet may be prevented by the uni-directional current energization of the impulse magnet.

3. A secondary clock comprising the usual arbor shaft, pawl and ratchet operating devices therefor, an impulse magnet of the direct current type for actuating said devices, a circuit for said impulse magnet and a rectifying unit in the magnet circuit to supply uni-directional current to the magnet from alternating current which is supplied to the clock to thereby obviate alternating current energization of the impulse magnet and to obviate chattering actuationsof the clock parts which would occur with A. C. energization of the magnet. 4

4. A secondary clock comprising a single supply circuit upon which alternating current and direct current impulses are impressed, an impulse magnet, chronological controlled switching means in said clock for selectively directing current to the impulse magnet of the clock and two rectifier devices in the secondary clock selectively brought into cooperating control over the flow of current to the impulse magnet by the said switching means, one rectifying device for providing for uni-directional current impulses to the impulse magnet upon the supply of alternating current impulses upon the supply line and for also blocking all flow of direct current impulses to the impulse magnet, the other rectifying device providing for uni-directional flow of current impulses to the impulse magnet of the clock upon the supply of alternating current impulses upon the supply line and for also permitting flow of direct current impulses to the impulse magnet from the supply line.

5. A secondary clock with an impulse magnet and clock parts controlled thereby, synchronization control and rectifying means for controlling synchronization of the clock and for providing uni-directional current flow to the impulse magnet at times when alternating current impulses are supplied to the clock and for unidirectional current flow to the impulse magnet at certain times when direct current impulses are supplied to theclock and for at times suppressing flow of current impulses to the impulse magnet, said synchronization control and rectifying means comprising parallel circuits connected to a. common circuit leading to the impulse magnet and also connected to a common supply circuit, a chronological controlled switching means in each parallel circuit, and a rectifying device in each parallel circuit, one rectifying device permitting current flow in one direction through one parallel circuit to the impulse magnet, the other rectifying device permitting current flow in the opposite direction through the other parallel circuit to the magnet and either rectifying device permitting uni-directional current flow of impulses to the impulse magnet with an A. C. supply of impulses to the supply circuit, one rectifying device being further disposed to block current flow to the impulse magnet upon direct current supply to one parallel circuit and the other rectifying device being adapted to permit current flow to the impulse magnet upon direct current flow to the other parallel circuit.

6. A secondary clock including an impulse magnet having an armature and chronological controlled switching means for selectively directing current flow to said magnet, pawl and ratchet devices for actuating the clock parts upon the energization of the impulse magnet, and means for preventing chattering of the armature and the magnet and of the clock parts operated thereby upon A. C. impulses being si pplied to the clock, comprising rectifying devices brought into circuit by the switching means which provide uni-directional current flow to the impulse magnet when alternating current impulses are received by the clock so that chattering actuations of the impulse magnet are prevented.

'7. The combination set forth in claim 6 in which the rectifying means comprises a pair of rectify- 15 .first mentioned rectifying device, and either rectifying device providing uni-directional current to the-impulse,magnet upon alternating current impulses being received by the clock.

- JAMES W. BRYCE. 

